Effect of thiamin on the content of fructose 2,6-bisphosphate in Euglena
1994
Yamaji, R. | Miyatake, K. | Enomoto, T. | Inui, H. | Shigeoka, S. | Kitaoka, S. | Nakano, Y.
1. Thiamin deprived Euglena cells contained twice as high a concentration of Fru-2,6-P2 in sufficient cells and the rate of the uptake of glucose from the medium was twice as great as that found in sufficient cells, indicating that Fru-2,6-P2 is responsible for the glycolysis. 2. Moreover, incubation of thiamin deprived cells with increasing thiamin concentrations caused a decrease of Fru-2,6-P2. The activity of Fru-6-P, 2-kinase was affected by thiamin and the activity of PFK-2 in thiamin deprived cells was 2.3 times greater than that observed in sufficient cells. 3. Incubating thiamin-deficient cells in a thiamin-containing medium, the activity of Fru-6-P, 2-kinase decreased rapidly and became the same activity as that found in thiamin sufficient cells. 4. In contrast, the two thiamin dependent 2-OGDC and PNOR activities showed a reverse relationship, being higher in thiamin-sufficient cells and lower in thiamin deficient cells. 5. We concluded that the carbohydrate metabolism of Euglena is regulated by Fru-2,6-P2 through an intracellular concentration of thiamin based on the present evidence.
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